This project represents part of a long-term research effort intending to describe and analyze the functions of cell groups within the superior olivary complex of the cat. The proposed work will be a collaborative effort involving a sensory neurophysiologist, C. Tsuchitani of the UTHSC-H, and a communication-signal processing theorist, D. H. Johnson of Rice University. The objective of this project is to determine the manner in which auditory information is encoded in the responses of lower auditory neurons by utilizing statistical communication theory, i.e., the theory of point processes, as the mathematical framework of the representation of discharge patterns. The proposed research will concentrate on the neural network which gives rise to the binaural responses of lateral superior olivary (LSO) neurons. Activity will be recorded extracellularly from single units in the LSO and from units in the anteroventral cochlear nucleus and the medial nucleus of the trapezoid body, which are presumed to innervate the LSO. Histological methods will be used to confirm unit location within these nuclei. Monaural stimuli will be used to elicit responses that will be used to establish the form of the statistical model of unit discharges. LSO unit discharges to binaural stimuli will serve to provide measures of the statistics of the inhibitory response and to develop the model of LSO unit binaural responses. Once the models of the LSO and its inputs have been established, the LSO network model will be developed and its consistency checked by comparing "input" and "output" quantities. Data collection and initial data analysis will be carried out at the UTHSC-H facility. The facilities at Rice University will provide the computing capabilities required for the statistical modeling of the single unit discharges.